Microcassiope xantusii (Stimpson, 1871)

Material examined. Two males from Islas Marietas (ICMyL MAZ 9313), and one male (ICMyL MAZ 9312A), and one ovigerous female (ICMyL MAZ 9312B) from La Boquita.

Remarks. This crab ranges from the Gulf of California to the Galápagos Islands (Villalobos-Hiriart et al. 1989). There are some records at Zihuatanejo, Acapulco, and the Huatulco regions (see Pereyra 1998) and at Bahía Navidad (Álvarez del Castillo et al. 1993). This species occurs in several habitats and is frequently found on corals. We registered some individuals on coral heads.